Date: Tue, 10 Dec 1996 03:25:57 GMT
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<TITLE>Multi-way versus One-way Constraints in User Interfaces: 
Experience with the DeltaBlue Algorithm</title>
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<H2>Multi-way versus One-way Constraints in User Interfaces: Experience
with the DeltaBlue Algorithm</H2>

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Authors: Michael Sannella, John Maloney, Bjorn Freeman-Benson, and Alan
Borning

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<em>Software--Practice and Experience</em>, Vol. 23 No. 5, (May 1993),
pages 529-566.  Preprint published as UW Tech Report 92-07-05.

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<H3>Abstract</H3>


The efficient satisfaction of constraints is essential to the performance
of constraint-based user interfaces.  In the past, most constraint-based
user interfaces have used one-way rather than multi-way constraints
because of a widespread belief that one-way constraints were more
efficient.  In this paper we argue that many user interface construction
problems are handled more naturally and elegantly by multi-way constraints
than by one-way constraints.  We present pseudocode for an incremental
multi-way constraint satisfaction algorithm, DeltaBlue, and describe
experience in using the algorithm in two user interface toolkits.  Finally,
we provide performance figures demonstrating that multi-way constraint
solvers can be entirely competitive in performance with one-way constraint
solvers.

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Click <!WA0><a href= "ftp://cs.washington.edu/tr/1992/07/UW-CSE-92-07-05a.PS.Z">
here</a> to get the postscript file.

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